Bone treatment systems and methods

ABSTRACT

Systems and methods for treating bone, such as vertebral compression fractures are disclosed. A method includes controllably applying energy to a bone cement volume outside of a patient&#39;s body to selectively accelerate the polymerization rate of the bone fill material volume prior to introduction into a bone. The method further includes sequentially introducing a plurality of cement carrying structures with the accelerated polymerization rate bone cement volume into the bone. A system for use in the method includes at least one elongated cement-carrying structure sized to carry a bone cement volume therein and an energy source operatively coupleable to the cement-carrying structure. The energy source applies energy to the bone cement volume to selectively accelerate a polymerization rate thereof. An elongated injector insertable into the bone has a passageway that removably receives the elongated cement-carrying structure to allow delivery of the accelerated polymerization rate bone cement into the bone.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No.60/926,936, filed on Apr. 30, 2007, the entire contents of which arehereby incorporated by reference and should be considered a part of thisspecification. This application is also related to the following U.S.patent applications: application Ser. No. 11/209,035 filed Aug. 22,2005; Provisional App. No. 60/842,805 filed Sep. 7, 2006, titled BoneTreatment Systems and Methods; and App. No. 60/713,521 filed Sep. 1,2005. The entire contents of all of the above applications are herebyincorporated by reference and should be considered a part of thisspecification.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to bone cement injection systems, and incertain embodiments provides a system for controlling the accelerationof polymerization of bone cement prior to delivery of the bone cementinto a bone.

2. Description of the Related Art

Osteoporotic fractures are prevalent in the elderly, with an annualestimate of 1.5 million fractures in the United States alone. Theseinclude 750,000 vertebral compression fractures (VCFs) and 250,000 hipfractures. The annual cost of osteoporotic fractures in the UnitedStates has been estimated at $13.8 billion. The prevalence of VCFs inwomen age 50 and older has been estimated at 26%. The prevalenceincreases with age, reaching 40% among 80-year-old women. Medicaladvances aimed at slowing or arresting bone loss from the aging have notprovided solutions to this problem. Further, the population affectedwill grow steadily as life expectancy increases. Osteoporosis affectsthe entire skeleton but most commonly causes fractures in the spine andhip. Spinal or vertebral fractures also cause other serious sideeffects, with patients suffering from loss of height, deformity andpersistent pain which can significantly impair mobility and quality oflife. Fracture pain usually lasts 4 to 6 weeks, with intense pain at thefracture site. Chronic pain often occurs when one vertebral level isgreatly collapsed or multiple levels are collapsed.

Postmenopausal women are predisposed to fractures, such as in thevertebrae, due to a decrease in bone mineral density that accompaniespostmenopausal osteoporosis. Osteoporosis is a pathologic state thatliterally means “porous bones”. Skeletal bones are made up of a thickcortical shell and a strong inner meshwork, or cancellous bone, ofcollagen, calcium salts and other minerals. Cancellous bone is similarto a honeycomb, with blood vessels and bone marrow in the spaces.Osteoporosis describes a condition of decreased bone mass that leads tofragile bones which are at an increased risk for fractures. In anosteoporosis bone, the sponge-like cancellous bone has pores or voidsthat increase in dimension making the bone very fragile. In young,healthy bone tissue, bone breakdown occurs continually as the result ofosteoclast activity, but the breakdown is balanced by new bone formationby osteoblasts. In an elderly patient, bone resorption can surpass boneformation thus resulting in deterioration of bone density. Osteoporosisoccurs largely without symptoms until a fracture occurs.

Vertebroplasty and kyphoplasty are recently developed techniques fortreating vertebral compression fractures. Percutaneous vertebroplastywas first reported by a French group in 1987 for the treatment ofpainful hemangiomas. In the 1990's, percutaneous vertebroplasty wasextended to indications including osteoporotic vertebral compressionfractures, traumatic compression fractures, and painful vertebralmetastasis. Vertebroplasty is the percutaneous injection of PMMA(polymethylmethacrylate) into a fractured vertebral body via a trocarand cannula. The targeted vertebrae are identified under fluoroscopy. Aneedle is introduced into the vertebrae body under fluoroscopic control,to allow direct visualization. A bilateral transpedicular (through thepedicle of the vertebrae) approach is typical but the procedure can bedone unilaterally. The bilateral transpedicular approach allows for moreuniform PMMA infill of the vertebra.

In a bilateral approach, approximately 1 to 4 ml of PMMA is used on eachside of the vertebra. Since the PMMA needs to be forced into thecancellous bone, the technique requires high pressures and fairly lowviscosity cement. Since the cortical bone of the targeted vertebra mayhave a recent fracture, there is the potential of PMMA leakage. The PMMAcement contains radiopaque materials so that when injected under livefluoroscopy, cement localization and leakage can be observed. Thevisualization of PMMA injection and extravasation are critical to thetechnique—and the physician terminates PMMA injection when leakage isevident. The cement is injected using syringes to allow the physicianmanual control of injection pressure.

Kyphoplasty is a modification of percutaneous vertebroplasty.Kyphoplasty involves a preliminary step consisting of the percutaneousplacement of an inflatable balloon tamp in the vertebral body. Inflationof the balloon creates a cavity in the bone prior to cement injection.The proponents of percutaneous kyphoplasty have suggested that highpressure balloon-tamp inflation can at least partially restore vertebralbody height. In kyphoplasty, some physicians state that PMMA can beinjected at a lower pressure into the collapsed vertebra since a cavityexists, when compared to conventional vertebroplasty.

The principal indications for any form of vertebroplasty areosteoporotic vertebral collapse with debilitating pain. Radiography andcomputed tomography must be performed in the days preceding treatment todetermine the extent of vertebral collapse, the presence of epidural orforaminal stenosis caused by bone fragment retropulsion, the presence ofcortical destruction or fracture and the visibility and degree ofinvolvement of the pedicles.

Leakage of PMMA during vertebroplasty can result in very seriouscomplications including compression of adjacent structures thatnecessitate emergency decompressive surgery. See “Anatomical andPathological Considerations in Percutaneous Vertebroplasty andKyphoplasty: A Reappraisal of the Vertebral Venous System”, Groen, R. etal, Spine Vol. 29, No. 13, pp 1465-1471 2004. Leakage or extravasationof PMMA is a critical issue and can be divided into paravertebralleakage, venous infiltration, epidural leakage and intradiscal leakage.The exothermic reaction of PMMA carries potential catastrophicconsequences if thermal damage were to extend to the dural sac, cord,and nerve roots. Surgical evacuation of leaked cement in the spinalcanal has been reported. It has been found that leakage of PMMA isrelated to various clinical factors such as the vertebral compressionpattern, and the extent of the cortical fracture, bone mineral density,the interval from injury to operation, the amount of PMMA injected andthe location of the injector tip. In one recent study, close to 50% ofvertebroplasty cases resulted in leakage of PMMA from the vertebralbodies. See Hyun-Woo Do et al, “The Analysis of PolymethylmethacrylateLeakage after Vertebroplasty for Vertebral Body Compression Fractures”,Jour. of Korean Neurosurg. Soc. Vol. 35, No. 5 (May 2004) pp. 478-82,(http://www.jkns.or.kr/htm/abstract.asp?no=0042004086).

Another recent study was directed to the incidence of new VCFs adjacentto the vertebral bodies that were initially treated. Vertebroplastypatients often return with new pain caused by a new vertebral bodyfracture. Leakage of cement into an adjacent disc space duringvertebroplasty increases the risk of a new fracture of adjacentvertebral bodies. See Am. J. Neuroradiol. 2004 February; 25(2):175-80.The study found that 58% of vertebral bodies adjacent to a disc withcement leakage fractured during the follow-up period compared with 12%of vertebral bodies adjacent to a disc without cement leakage.

Another life-threatening complication of vertebroplasty is pulmonaryembolism. See Bernhard, J. et al, “Asymptomatic diffuse pulmonaryembolism caused by acrylic cement: an unusual complication ofpercutaneous vertebroplasty”, Ann. Rheum. Dis. 2003;62:85-86. The vaporsfrom PMMA preparation and injection also are cause for concern. SeeKirby, B. et al., “Acute bronchospasm due to exposure topolymethylmethacrylate vapors during percutaneous vertebroplasty”, Am.J. Roentgenol. 2003; 180:543-544.

In both higher pressure cement injection (vertebroplasty) andballoon-tamped cementing procedures (kyphoplasty), the methods do notprovide for well controlled augmentation of vertebral body height. Thedirect injection of bone cement simply follows the path of leastresistance within the fractured bone. The expansion of a balloon alsoapplies compacting forces along lines of least resistance in thecollapsed cancellous bone. Thus, the reduction of a vertebralcompression fracture is not optimized or controlled in high pressureballoons as forces of balloon expansion occur in multiple directions.

In a kyphoplasty procedure, the physician often uses very high pressures(e.g., up to 200 or 300 psi) to inflate the balloon which crushes andcompacts cancellous bone. Expansion of the balloon under high pressuresclose to the cortical bone can fracture the cortical bone, typically theendplates, which can cause regional damage to the cortical bone with therisk of cortical bone necrosis. Such cortical bone damage is highlyundesirable as the endplate and adjacent structures provide nutrientsfor the disc.

Kyphoplasty also does not provide a distraction mechanism capable of100% vertebral height restoration. Further, the kyphoplasty balloonsunder very high pressure typically apply forces to vertebral endplateswithin a central region of the cortical bone that may be weak, ratherthan distributing forces over the endplate.

There is a general need to provide bone cements and methods for use inthe treatment of vertebral compression fractures to provide a greaterdegree of control over the introduction of cement and to provide betteroutcomes. The present invention meets this need and provides severalother advantages in a novel and nonobvious manner.

SUMMARY OF THE INVENTION

Certain embodiments of the invention provide bone cement injectors andcontrol systems that allow for vertebroplasty procedures that injectcement having a substantially constant viscosity over an extended cementinjection interval.

In some embodiments, a computer controller is provided to control cementflow parameters in the injector and energy delivery parameters forselectively accelerating polymerization of bone cement before the cementcontacts the patient's body.

In accordance with one embodiment, a method of treating a bone isprovided. The method comprises providing a plurality of cement carryingstructures, each structure carrying a mixed bone cement volume having apredetermined polymerization rate at which the bone cement polymerizesto a selected endpoint. The method further comprises controllablyapplying energy from an energy source to the bone cement volume outsideof a patient's body to selectively accelerate the polymerization rate ofthe bone cement volume prior to introduction of the bone cement into thebone and sequentially introducing the mixed bone cement volumes withsaid accelerated polymerization rate into the bone.

In accordance with another embodiment, a method of treating a vertebrais provided. The method comprises providing at least one elongatedstructure carrying a mixed bone fill material and controllably applyingenergy from an energy source to the mixed bone fill material toselectively accelerate polymerization of the bone fill material outsideof a patient's body. The method further comprises inserting at least aportion of an elongated injector into a vertebral body, removablyinserting at least a portion of the at least one elongated structureinto the elongated injector, and delivering the mixed bone fill materialwith said accelerated polymerization into the vertebral body.

In accordance with another embodiment, a system for treating a vertebrais provided. The system comprises at least one elongated cement-carryingstructure having a interior space for receiving a bone fill material andan energy source operatively coupleable to the cement-carrying structureoutside of a patient's body, the energy source configured to applyenergy to the bone fill material to selectively accelerate apolymerization rate of the bone fill material. The system furthercomprises an elongated injector, at least a portion of which isinsertable into a vertebral body, the elongated injector comprising apassageway sized to removably receive at least a portion of theelongated cement-carrying structure so as to allow delivery of the bonefill material with said accelerated polymerization rate through theinjector into the vertebral body.

In accordance with another embodiment, a system for treating bone isprovided. The system comprises an elongated injector, at least a portionof which insertable into a bone and at least one cement-carryingstructure configured to contain a volume of a mixed bone fill material,the cement carrying structure releasably coupleable to the injector. Thesystem further comprises at least one housing member comprising anenergy emitter and sized to removably receive at least a portion of thecement-carrying structure, the energy emitter configured to apply energyto the bone fill material outside of a patient's body when thecement-carrying structure is coupled to the housing to therebyselectively accelerate the polymerization of the mixed bone fillmaterial.

In accordance with still another embodiment, a kit for treating bone isprovided. The kit comprises a plurality of elongated cement-carryingdevices configured to receive a volume of mixed bone fill materialtherein, an elongated bone fill material injector, and at least onehousing configured to removably receive at least one of the plurality ofelongated cement-carrying devices in a passage thereof. The housingcomprises an energy emitter configured to apply energy to the mixed bonefill material in the cement-carrying device disposed in the housing toselectively accelerate the polymerization rate of a selected volume ofthe mixed bone fill material to a selected endpoint. The kit furthercomprises an energy source coupleable to the energy emitter to deliverenergy thereto.

These and other objects of the present invention will become readilyapparent upon further review of the following drawings andspecification.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to better understand the invention and to see how it may becarried out in practice, some preferred embodiments are next described,by way of non-limiting examples only, with reference to the accompanyingdrawings, in which like reference characters denote correspondingfeatures consistently throughout similar embodiments in the attacheddrawings.

FIG. 1 is a schematic perspective view of one embodiment of a bonecement injection system.

FIG. 2 is another schematic view of the bone cement injection system ofFIG. 1.

FIG. 3 is a schematic view of a thermal emitter component of the systemof FIG. 1.

FIG. 4 is a schematic block diagram of one bone cement injection methodutilizing the system of FIGS. 1-2.

FIG. 5A is a graphical representations of a first step of one bonecement injection method.

FIG. 5B is a graphical representation of a subsequent step of assemblingcomponents in one embodiment of the bone cement injection method.

FIG. 5C is a graphical representation of a subsequent step of applyingenergy to cement and injecting cement into a vertebra according to bonecement injection method.

FIG. 5D is another schematic view of the injecting step in the bonecement injection method.

FIG. 6 is a schematic view of another embodiment of a bone cementinjector system.

FIG. 7 is a schematic view of another embodiment of a bone cementinjector system.

FIG. 8A is a schematic view of a step in a bone cement injection method.

FIG. 8B is a schematic view of another step of applying energy to cementand injecting cement into a vertebra according to the bone cementinjection method of FIG. 8A.

FIGS. 9A-9B are schematic cross-sectional views of one embodiment of abone cement injector.

FIG. 10A is a graphical representations of a step of one bone cementinjection method.

FIG. 10B is a graphical representation of another step of assemblingcomponents in the bone cement injection method.

FIG. 10C is a graphical representation of another step of applyingenergy to cement and injecting cement into a vertebra according to thebone cement injection method.

FIG. 10D is another schematic view of an injecting step of the bonecement injection method.

FIG. 10E is a schematic view of preparing a second injector according toone embodiment of the bone cement injection method.

FIG. 10F is another schematic view of preparing the second injectoraccording to the bone cement injection method.

FIG. 10G is a schematic view of an injecting step according to the bonecement injection method.

FIG. 11 is a schematic view of another embodiment of a bone cementinjector system.

FIG. 12A is a graphical representation of one step of a bone cementinjection method.

FIG. 12B is a graphical representation of another step of assemblingcomponents of the bone cement injector system.

FIG. 12C is a graphical representation of another step of applyingenergy to cement and injecting cement into a vertebra according to thebone cement injection method.

FIG. 12D is another schematic view of the injecting step of the bonecement injection method.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

For purposes of understanding the principles of the invention, referencewill now be made to the embodiments illustrated in the drawings andaccompanying text that describe certain embodiments of the invention. Asbackground, in certain embodiments a vertebroplasty procedure wouldinsert the system of FIGS. 1-5D through a pedicle of a vertebra, or by aparapedicular approach, for accessing the osteoporotic cancellous bone.The initial aspects of the procedure are similar to a conventionalpercutaneous vertebroplasty wherein the patient is placed in a proneposition on an operating table. The patient is typically under conscioussedation, although general anesthesia is an alternative. The physicianinjects a local anesthetic (e.g., 1% Lidocaine) into the regionoverlying the targeted pedicle or pedicles as well as the periosteum ofthe pedicle(s). Thereafter, the physician uses a scalpel to make a 1 to5 mm skin incision over each targeted pedicle. Thereafter, theintroducer is advanced through the pedicle into the anterior region ofthe vertebral body, which typically is the region of greatestcompression and fracture. The physician confirms the introducer pathposterior to the pedicle, through the pedicle and within the vertebralbody by anteroposterior and lateral X-Ray projection fluoroscopic views.The introduction of infill material as described below can be imagedseveral times, or continuously, during the treatment depending on theimaging method.

Definitions

“Bone cement, bone fill or fill material, infill material orcomposition” includes its ordinary meaning and is defined as anymaterial for infilling a bone that includes an in-situ hardenablematerial or that can be infused with a hardenable material. The fillmaterial also can include other “fillers” such as filaments,microspheres, powders, granular elements, flakes, chips, tubules and thelike, autograft or allograft materials, as well as other chemicals,pharmacological agents or other bioactive agents.

“Flowable material” includes its ordinary meaning and is defined as amaterial continuum that is unable to withstand a static shear stress andresponds with an irrecoverable flow (a fluid)—unlike an elastic materialor elastomer that responds to shear stress with a recoverabledeformation. Flowable material includes fill material or composites thatinclude a fluid (first) component and an elastic or inelastic material(second) component that responds to stress with a flow, no matter theproportions of the first and second component, and wherein the aboveshear test does not apply to the second component alone.

“Substantially” or “substantial” mean largely but not entirely. Forexample, substantially may mean about 50% to about 99.999%, about 80% toabout 99.999% or about 90% to about 99.999%.

“Vertebroplasty” includes its ordinary meaning and means any procedurewherein fill material is delivered into the interior of a vertebra.

“Osteoplasty” includes its ordinary meaning and means any procedurewherein fill material is delivered into the interior of a bone.

In one embodiment, as depicted in FIG. 1, a system 10A is shown thatincludes a first component 100 including a bone cement-carryingstructure 105 that can have an elongated sleeve 110. The elongatedsleeve 110 can be of a thin-wall polymer or metal and defines aninterior space or channel 112 into which a volume of a pre-polymerizedbone cement 150 mixture can be loaded (FIG. 2). In one embodiment, thepre-polymerized bone cement mixture can be an uncured bone cementmixture. In another embodiment, the pre-polymerized bone cement mixturecan be a partially cured bone cement mixture. The first component 100optionally includes a proximal handle or grip portion 116 with thecement-carrying structure 105 being coupleable with or removablyreceivable in a second component or bone cement injector 120, describedbelow. As can be seen in FIG. 1, the elongated sleeve 110 and interiorspace or channel 112 can have an open proximal end 122 for loadingcement 150 into the structure 105 and an open distal outlet 124. Theopen proximal end 122 can, in one embodiment, have an interlock element(e.g., a Luer fitting) for coupling with a cement source, such as asyringe, for loading cement 150 into the structure 105.

The cement-carrying structure 105 and its interior channel 112 can incertain embodiments be round or polygonal in cross-section, have aconstant diameter along its length or a stepped diameter, as shown inFIG. 1, or can have a flattened shape to provide a ribbon-like volume ofcement therein, as described below. In one embodiment, thecement-carrying structure 105 can be a very thin walled polymer sleeveand can be transparent or translucent to allow observation of thecement. The cement-carrying structure 105 can have a capacity of atleast 0.10 cc, at least 0.50 cc, at least 1.0 cc and at least 2.0 cc ofbone cement.

The second component or bone cement injector 120 of the system 10A canbe similar to commercially available injectors with a handle portion 128and an elongated extension portion 130 that can be of a rigid tubularmaterial. An interior space or receiving portion 132 in the injector 120can be sized to at least partly receive the cement-carrying structure105 of the first component 100 as can be seen in FIG. 1. The bone cementinjector 120 and more particularly its interior space 132 with an openproximal end 133 and an open termination or outlet 135 allows for bonecement flow therethrough into the interior of a bone. As can beunderstood in FIG. 1, the proximal handle portions 116 and 128 of thefirst and second components 100, 120 can releaseably interlock using anysuitable mechanism known in the art.

In another view of the embodiment as shown in FIG. 2, the firstcomponent 100 and cement-carrying structure 105 can be coupled to anenergy source, such as an electrical source 140 that provides fordelivery of thermal energy from an emitter mechanism 144 within thecement-carrying structure 105. In one embodiment, the thermal energyemitter 144 can be carried substantially throughout the length of thecement-carrying structure 105. In other embodiments, the thermal energyemitter 144 can be carried within a proximal region, a medial region ora distal region of the cement-carrying structure 105. The system canfurther include a controller 145 operatively coupled to the energysource 140. The source 140 can preferably cause thermal effects in thebone cement 150 contained in the cement-carrying structure 105 andaccelerate the polymerization of the bone cement.

As depicted in FIG. 2, the bone cement 150 can have a predeterminedworking time for polymerizing from an initial state to a selectedendpoint (e.g., predetermined endpoint) of at least 8 minutes, 10minutes, 12 minutes, 14 minutes, 16 minutes, 18 minutes, 20 minutes, 25minutes, 30 minutes and 40 minutes, as disclosed in co-pendingProvisional Application Ser. No. 60/899,487 filed Feb. 5, 2007 andtitled Bone Treatment Systems and Methods, the entire contents of whichare hereby incorporated by reference and should be considered a part ofthis specification. The selected polymerization endpoint provides thebone cement 150 in a partly polymerized condition having a selectedviscosity range that substantially inhibits cement extravasation.Herein, the terms ‘polymerization rate’ and ‘working time’ may be usedalternatively to describe the interval in which the cement polymerizesfrom the initial or just-mixed state to the selected endpoint.

As can be understood from FIG. 2, the energy source can accelerate apolymerization rate of the bone cement 150 by at least 20%, 30%, 40%,50%, 60%, 70%, 80%, 90% and 95%. In another aspect of the invention, theenergy source 140 and controller 145 can accelerate the polymerizationrate of the cement to the selected endpoint in less than 1 second, 5seconds, 10 seconds, 20 seconds, 30 seconds, 45 seconds, 60 seconds and2 minutes.

Referring to the embodiment illustrated in FIGS. 2 and 3, the electricalsource 140 and controller 145 can be coupled to the first component 100by an electrical connector 152 and cable 154. As can be seen in FIG. 3,the wall 155 of the cement-carrying structure 105 can carry the thermalenergy emitter 144, which can include a polymeric positive temperaturecoefficient of resistance (PTCR) material with spaced apart interlacedsurface electrodes 158A and 158B as described in co-pending ProvisionalApplication No. 60/907,468 filed Apr. 3, 2007 titled Bone TreatmentSystems and Methods. In this embodiment, the thermal emitter 144 andwall 155 resistively heat and cause controlled thermal effects in thecement 150 contained therein. It should be appreciated that FIG. 3 is aschematic representation of the cement-carrying structure 105 and canhave any elongated or truncated shape or geometry, tapered ornon-tapered form, or comprise the wall of a collapsible thin-filmelement, such as a bladder or balloon-like member. Further, the positive(+) and negative (−) polarity electrodes can have a spaced apartarrangement, for example a radially spaced apart arrangement, ahelically spaced apart arrangement, an axially spaced apart arrangementor any combination thereof. This resistively heated PTCR material of theemitter 144 can further generate a signal that indicates flow rate, asdescribed in Provisional Application No. 60/907,468, which in turn canbe utilized by the controller 145 to modulate the energy applied to thecement 150.

As can be understood from FIGS. 1 & 2, the system 10A can furtherinclude a cement actuation mechanism or pressure mechanism 160 formoving the cement 150 through the first component 100 and/or injector120 into the interior of a vertebra 172. The actuation mechanism 160 canbe a simple piston or plunger, as in a syringe 162, as indicated in FIG.2. Alternatively, a hydraulic fluid flow mechanism can be used to applypressure to cement 150 in the first component 100 and/or injector 120.However, any other form of pump (e.g., a pneumatic pressure mechanism)may be used to apply pressure to the cement 150 to facilitate the flowof bone cement 150 through the component 100 and/or injector 120.

Now turning to FIG. 4, a method, corresponding to one embodiment of theinvention, utilizing the system 10, comprises the following steps asshown in the block diagram: (i) providing the cement-carrying structure105 of FIGS. 1 and 2 that carries a pre-polymerized bone cementindicated at 170A; (ii) providing a source 140 for causing thermaleffects in the cement 150 indicated at 170B; (iii) acceleratingpolymerization of the cement 150 when the cement 150 is not in contactwith the patient's body indicated at 170C; and (iv) introducing theaccelerated-polymerization cement 150′ into the interior of a vertebra172 thru a cement injector 120 indicated at 170D.

FIGS. 5A-5D graphically depicts one method for delivering bone cement150, as described in the block diagram of FIG. 4. In FIG. 5A, the bonecement injector 120 of FIG. 1 is inserted into a vertebra 172, forexample by a transpedicular access or a parapedicular access. In FIG.5A, it also can be seen that a first component 100 and cement-carryingstructure 105 is prepared for introduction into the receiving portion132 of the cement injector 120. FIG. 5B next depicts the insertion ofthe cement-carrying structure 105 into the receiving portion 132 of thecement injector 120 and the coupling of a source of cement 150 to acement-carrying structure 105. In the illustrated embodiment, the sourceof bone cement 150 is a syringe 162.

FIG. 5C next depicts another step in one embodiment in which a flow ofbone cement 150 is injected from the syringe 162 into the channel 112 ofthe cement-carrying structure 105. FIG. 5C further depicts the actuationof the electrical source 140 and the controller 145 to thereby heat theemitter 144 and apply thermal energy from the emitter 144 andcement-carrying structure 105 to the flow of cement 150 to therebyaccelerate polymerization of the cement flow through the thermal energyemitter 144 and cement-carrying structure 105. FIG. 5D next depicts theflow of ‘accelerated polymerization’ bone cement 150′ into the interior174 cancellous bone of the vertebra 172 from the outlet 135 of thecement injector 120. As depicted in FIG. 5D, the method provides amodified volume of cement 150′ that first contacts bone having an‘accelerated-polymerization’ state within a selected viscosity rangethat substantially prevents cement extravasation. As can be seen inFIGS. 5C-5D, the thermal energy can be applied to the flowing cement.Alternatively, thermal energy can be applied from the emitter 144 andthe structure 105 to the cement 150 that is introduced into thecement-carrying structure 105 but is not flowing, wherein a selectedlevel of energy is applied and then the accelerated-polymerizationcement volume is injected through the system. As can be seen in FIGS.5C-5D, in one embodiment the controller 145 and energy source 140 areinterlinked to the pressure source 160 so that variations in flow ratecan modulate energy application to the cement, or the cement flow ratecan be modulated to variations in the applied energy. With continuedreference to FIGS. 5C-5D, in one embodiment the controller 145 canmodulate energy application to the cement flow from the source 140 basedat least in part on the flow rate as determined by the systems andmethods described in co-pending Provisional Application No. 60/907,468filed Apr. 3, 2007 titled Bone Treatment Systems and Methods.

FIG. 6 illustrates another system embodiment 10B for use in acorresponding method which is substantially equivalent to the methoddepicted in FIGS. 5A-5D. As can be seen in FIG. 6, the first componentindicated at 100 is similar to that of FIG. 1 except that thecement-carrying structure 105 and the PTC thermal emitter 144 are lesselongated and can be detachably mated with the bone cement injector 120as in FIGS. 1-2 and FIGS. 5A-5D. A Luer-fitting (not shown) to couplethe first component 100 and the injector 120 can be used in oneembodiment. It can be understood that the system embodiment 10B canapply energy to bone cement 150 that flows through the cement-carryingstructure 105 and thermal emitter 144, whereas the elongated firstcomponent 100 of FIGS. 1-2 and FIGS. 5A-5D can apply energy to cement150 that is non-flowing or flowing within the cement-carrying structure105, or any combination of energy application intervals to non-flowingand flowing cement 150.

FIG. 7 illustrates another system embodiment 10C similar to the systemof FIG. 6. The first component 100 of FIG. 7 includes thecement-carrying structure 105 and PTC thermal emitter 144 in a conduitmember 180 that is proximal to the handle 128 of the bone cementinjector 120 with cooperating Luer-fittings 182 a and 182 b fordetachable mating of the components. As in the embodiment of FIG. 6, thefirst component 100 and thermal emitter 144 are remote from thepatient's body. As in the embodiment of FIG. 6, the first component 100of FIG. 7 and thermal emitter 144 can apply energy to cement 150 that isnon-flowing within the system.

FIGS. 8A-8B graphically depict a method of the invention utilizing thesystem 10B of FIG. 6. It can be seen that the bone cement injector 120of FIG. 1 is inserted into the vertebra 172 as described previously. InFIG. 8A, the first component 100 with a non-elongated cement-carryingstructure 105 and thermal emitter 144 is connected to the electricalsource 140 and controller 145. FIG. 8B then depicts several steps, as inFIG. 4 (and FIGS. 5B-5D), including: (i) coupling the first component100 with the structure 105 and thermal emitter 144 to the cooperatinghandle portion 128 of the cement injector 120; (ii) coupling the source162 of bone cement 150 and pressure source 160 to the cement-carryingstructure 105; and (iii) injecting a flow of bone cement 150 from thesource 162 through the cement-carrying structure 105 and actuatingelectrical source 140 and emitter 144 to apply thermal energy from theemitter 144 and structure 105 to the flow of cement 150 to therebyaccelerate polymerization of the cement flow through the system, therebyproviding a flow of ‘accelerated-polymerization’ bone cement 150′ in theinterior 174 of the vertebra 172. In a another step of the method asshown in FIG. 8B, the application of energy to the cement can occur whenthe bone cement is retained within the system, not in contact with thepatient's body and outward from the patient's body or skin 185. It canbe understood that a similar bone cement injection method could be usedwith the system 10C of FIG. 7.

FIGS. 9A and 9B illustrate optional cross-sections of the flow channel112 through a cement-carrying structure 105 and PTCR thermal emitter 144or any other type of thermal emitter, with the sectional view of FIGS.9A-9B in the exemplary embodiment of FIG. 6. It has been found thatflattened or ribbon-like cement flows, as in FIG. 9A, can be most easilyheated by a heating element since a larger cement surface area isexposed to the heat transferred through the wall 155 of the structure.Similarly, FIG. 9B shows another configuration of a channel 112 with alarge surface area when compared to the cement flow cross-section.

Now turning to FIGS. 10A-10G, another bone cement injection method isdepicted that utilizes a system similar to the system 10A of FIGS. 1 and2. In this embodiment, a bone cement injector 120 as in FIG. 1 isinserted into a vertebra 172 as described previously. In this methodwhich is also described by the block diagram of FIG. 4, a plurality offirst components 100 (here shown as four components 100 a-100 d) withelongated cement-carrying structures 105 and thermal emitters 144 areused to prepare accelerated-polymerization cement 150′ in advance ofinserting the cement-carrying structures 105 into the bone cementinjector 120. It should be appreciated that the first components 100 cannumber from two to ten or more, depending on their capacity and thenumber of vertebrae targeted for treatment. In one embodiment, theplurality of first components 100 a-100 d can be used to prepareaccelerated-polymerization cement 150′ having the same level ofpolymerization. In another embodiment, at least two of the plurality offirst components 100 a-100 d can be used to prepareaccelerated-polymerization cement 150′ having a different level ofpolymerization.

In one step of the illustrated method, FIG. 10A illustrates filling thecomponent 100 a with a just-mixed bone cement 150, for example, from asource of bone cement such as a syringe 162. FIG. 10B next illustratesthe coupling of the component 100 a and the emitter 144 to the connector152 of the electrical source 140 and controller 145. Further, FIG. 10Bdepicts the actuation of the electrical source 140 and controller 145 tothereby cause the energy emitter 144 (e.g., PTCR emitter) to applythermal energy from the emitter 144 and cement-carrying structure 105 tothe contained volume of cement 150 to thereby accelerate polymerizationof the cement disposed within the cement carrying structure 105. FIG.10B further illustrates filling the other components 100 b-100 d withthe just-mixed, pre-polymerized bone cement 150 from a source or syringe162.

Now referring to FIG. 10C, it can be seen that the component 100 a isde-coupled from the connector 152 and the electrical source 140. Then,the component 100 a is inserted into the cement injector 120, at least aportion of which has been inserted into the vertebra 172 to provideaccess to the vertebra 172. Thus, it can be understood that thecomponent 100 a is in operative contact with the tissue and is notconnected to the energy source 140.

FIG. 10D shows another step in the illustrated embodiment in which thecomponent 100 a carrying the accelerated polymerization cement 150′ isfully inserted into the cement injector 120. Further, FIG. 10E depictscoupling a pressure source 160 to the component 100 a, which in oneembodiment is a disposable syringe 188 filled with a predeterminedvolume of saline or any biocompatible fluid or gel 190 having a volumethat approximates the volume of cement 150′ carried within the component100 am or at between 50% and 99% of said cement volume, or between 75%and 90% of said cement volume, or at less than 50% of said cementvolume.

FIG. 10E illustrates another step where the actuation of the pressuresource 160 causes the gel 190 to be introduced into the component 100 ato displace the accelerated polymerization cement 150′ and inject saidcement 150′ into the interior 174 of the vertebra 172. As in previousmethods, the method of FIGS. 10-10E thus provides a modified volume ofthe cement 150′ that first contacts bone having an‘accelerated-polymerization’ state with a selected viscosity range thatsubstantially prevents cement extravasation. FIG. 10E furtherillustrates coupling a component 100 b to a connector 152 and anelectrical source 140, and also depicts the actuation of the electricalsource 140 and emitter 144 to apply thermal energy to the containedvolume of cement 150 within the component 100 b.

FIG. 10F illustrates the removal of the empty component 100 a from thecement injector 120 and further depicts de-coupling the component 100 bfrom the connector 152 and electrical source 140, and the partialinsertion of that cement-filled component 100 b into the cement injector120. FIG. 10G next illustrates another step in the illustratedembodiment in which the coupling and actuation of the pressure source160 to the component 100 b to thereby introduce an additional volume ofaccelerated polymerization cement 150′ into the interior 174 of thevertebra 172. It can be seen in FIG. 10G that the cement volume in thevertebra has increased in perimeter from 194 to 194′. The additionalvolumes of cement in the components, indicated by 100 c and 100 d, ofFIG. 10G can be utilized as described above to accelerate thepolymerization with each component, and then sequentially inject thecement volumes or portions thereof into bone.

FIG. 11 illustrates another embodiment or system 10D that is similar tothat of FIGS. 1-2 that is utilized to perform the method of FIG. 4 andFIGS. 10A-10G. The embodiment of FIG. 11 differs only in that thethermal energy emitter 144 is not carried in the wall 155 of the firstcomponent 100 a′. In the embodiment depicted in FIG. 11, the thermalenergy emitter 144 (e.g., a PTCR emitter, as described above) can beremovably disposed within a disposable or non-disposable body or housing200 (e.g., disposed within a recess in the housing 200). The housing 200can receive and engage the wall 155 of the first component 100 a′ andcement-carrying structure 105′. In the embodiment of FIG. 11, a thermalenergy emitter 144 is within a core body portion 210 of the housing 200,which has a receiving bore 212 for receiving the elongatedcement-carrying structure 105′ of the first component 100 a′. The corebody portion 210 can be surrounded by an insulative body portion 214. Inone embodiment, the core body portion 210 and thermal energy emitter 144can be configured substantially as the heat emitter of FIG. 3, withoptional thicker cross-sections. In FIG. 11, it can be seen that thebody 200 and emitter 144 can again be coupled to the connector 152,electrical source 140 and controller 145.

FIG. 11 illustrates another component of system 10D (which also can belinked to the systems 10A-10C) that can include a data acquisitionsystem 220 and display(s) 222 coupleable to the controller 145, whereinthe data acquisition system 220 receives a signal of at least onepolymerization parameter of the accelerated polymerization cement 150′within the system and displays said at least one polymerizationparameter in the display(s) 222. For example, the emitter 144 canfunction as an electrode to sense said at least one polymerizationparameter, said sensed parameter transmitted to the data acquisitionsystem 220 via a signal from the emitter 144 through the controller 145to the data acquisition system 220. In one embodiment, the data andsignal system 220 can provide at least one of: (i) the time intervalremaining to a selected polymerization endpoint, (ii) the calculatedcement viscosity, (iii) the cement temperature, (iv) the rate of changeof the temperature or viscosity, (v) the acceleration or rate of changeof the cement temperature or viscosity, (vi) the elapsed time sinceenergy was applied to the cement, and (vii) the amount of energy appliedto the cement. In the embodiment illustrated in FIG. 11, the data andsignal system 220 has at least one visual display indicated at 222, butthe signal communicated by the data acquisition system 220 can also bean aural signal, a tactile signals and the like.

FIGS. 12A-12D depict a method of use of system 10D, which is similar tothe method of FIGS. 10A-10G, so that each step of this method need notbe repeated in detail. FIG. 12A illustrates filling the first component100 a′ with a just-mixed bone cement 150, such as PMMA, from a cementsource 162. FIG. 12B depicts de-coupling the cement source 162 from thefirst component 100 a′, and then inserting the cement-carrying structure105′ into the receiving channel 212 of the body 200 that carries thethermal emitter 144.

FIG. 12C depicts the steps of filling a plurality of components 100a′-100 c with cement 150, and then inserting at least one in a thermalenergy application body 200, as in FIG. 10B. FIG. 12C further depictsactuating the electrical source 140 and controller 145 to thereby causethe thermal emitter 144 in each of the bodies 200 to apply thermalenergy from the emitter 144 to the engaged cement-carrying structure105′ to the contained volume of cement 150 to thereby acceleratepolymerization of the cement 150. In one embodiment, the controller 145can control the application of energy from the thermal energy emittersso that substantially the same level of energy is transmitted to the boncement 150 in the bodies 200 via the respective emitters in the bodies200. In another embodiment, the controller 145 can control theapplication of energy from the thermal energy emitters so that differentlevels of energy are transmitted from the emitters in the respectivebodies 200 to the bone cement 150 in the components 100 a′-100 cdisposed in the bodies 200.

FIG. 12D then illustrates removing a component 100 a′ from the body 200and inserting the component 100 a′ that then carries the acceleratedpolymerization cement 150′ into the cement injector 120. As can beunderstood, the subsequent steps of FIGS. 10D-10G need not be repeatedin the drawings. A pressure source 160 can be coupled to a component 100a′ to introduce the cement 150′ into the bone, and the sequence isfollowed with additional volumes of accelerated polymerization cement.During the sequential treatment and introduction of the cement 150′ intothe vertebra, the display(s) 222 can inform the physician of operationaland polymerization parameters of the cement, and the physician canutilize the controller to apply energy to the cement to thus allow forthe accelerated polymerization cement 150′ to have substantially thesame viscosity cement to be used throughout a procedure, even if theprocedure may last 30 minutes, 60 minutes or more. The system and energysource 140 can preferably apply energy of at least 0.01 Watt, 0.05 Watt,0.10 Watt, 0.50 Watt and at least 1.0 Watt. In another aspect, theenergy source and controller are configured for accelerating thepolymerization rate of the bone cement to a selected endpoint in lessthan 1 second, 5 seconds, 10 seconds, 20 seconds, 30 seconds, 45seconds, 60 seconds and 2 minutes.

The system of FIGS. 11-12D can use any energy source as a thermalemitter 144, such as a recirculating non-ambient temperature fluidsource, a radiofrequency source, an electrical source, a resistive heatsource, a positive temperature coefficient of resistance (PTCR) constanttemperature heat source, a non-coherent light source, a laser source, aLED source, a microwave source, a magnetic source and an ultrasoundsource. In summary, one embodiment of the invention comprises at leastone cement-carrying structure 105′ for carrying pre-polymerized bonecement 150, the structure releasably coupleable with a bone cementinjector 120; and an energy source 140 operatively coupleable to thestructure 105′ for causing controlled thermal effects in the bone cementtherein for accelerating the polymerization thereof. The emitter 144 andenergy source 140 can be carried by the cement-carrying structure 105′,or the thermal energy emitter component 144 can be within an assemblywith a receiving portion 132 that receives the cement-carrying structure105′. The system has a controller 145 that can controllably apply energyto at least one of a flow of cement and non-flowing cement 150. Inanother embodiment, the cement-carrying structure 105′ can include aflexible sleeve, a rigid sleeve, a bladder, a syringe, a tube, aconduit, a bellows, a non-compliant sac or balloon, a compliant sac orballoon, and an elastomeric thin-wall member, any of which can becoupled to a cement injector 120. It should be appreciated that, in oneembodiment, the body 200 also can carry a cooling system fordecelerating polymerization of the cement 150 contained within thecement carrying structure 105′ disposed within the body 200, and onebone cement injection method using the systems disclosed above caninclude accelerating polymerization of the cement 150 and then stallingor decelerating polymerization by cooling the cement 150 to maintain thecement generally in a ready state for use by the physician. Accordingly,the cooling system can be used to maintain the bone cement 150 in apredetermined state (e.g., at a generally constant temperature orviscosity), thereby extending the working time of the cement 150. Anysuitable cooling system known in the art may be used, such ascirculation of a cooling fluid or cryogenic fluid. A further discussionof bone treatment systems and methods, including cooling systems, can befound in U.S. patent application Ser. No. 11/469,769 filed Sep. 1, 2006,the entire contents of which are hereby incorporated by reference andshould be considered a part of this specification.

The cooling system can be an active cooling system or a passive coolingsystem. In one embodiment (not shown), the cooling system can includes athermoelectric system with at least one element (e.g., a Peltierelement) in contact with a thermally conductive wall portion of thethermal energy application body. In another embodiment (not shown), thecooling system can include a chilled fluid circulation system withchannels disposed proximate the wall portion of thermal energyapplication body. In another embodiment (not shown) the cooling systemcan include a Freon system with an expansion channel inside the wallportion of the thermal energy application body. However, the coolingsystem can include other suitable active cooling arrangements. In stillanother embodiment (not shown), the cooling system can include a heatpipe system with at least one elongate channel or concentric channel inthe wall portion of the thermal energy application body, which wicksheat away from the thermal energy application body to a heat exchangercomponent. In yet another embodiment (not shown), the cooling system canbe a passive system that includes an open cell graphite structure forconducting heat away from the thermal energy application body to a heatexchanger component. In such an embodiment, the open cell graphite canbe PocoFoam™ manufactured by Poco Graphite, Inc. 300 Old Greenwood Road,Decatur, Tex. 76234.

In one embodiment as in FIG. 11, the body 200 for receiving thecement-carrying structure 105′ has a cooperating bore 212 that canprovide a wall-to-wall interface 240 (FIG. 12B) between the wall of theemitter 144 that substantially contacts and engages the wall 155 of thecement-carrying structure 105′ to provide heat transfer thereto. Inother embodiments, the interface 240 can be a fluid interface with thewall 155, a gel or elastomer interface with the wall 155, or heated gasor vapor interface with the wall 155. Further, the body 200 (not shown)can have a plurality of receiving portions 132 for receiving any rigid,flexible or bladder-type cement-carrying structure 105′.

In another aspect of the invention, a method for bone cement injectionin an osteoplasty procedure comprises (a) providing a bone cementinjector body 120 carrying a PTCR or NTCR material (positive temperaturecoefficient of resistance or negative temperature coefficient ofresistance); (b) causing cement flow through the injector body 120; and(c) measuring an electrical parameter of the PTCR or NTCR material inresponse to heat transfer from the cement flow to the PTCR or NTCRmaterial to thereby determine a selected parameter of the cement flow.It has been found that the change in impedance of the temperaturecoefficient material can be used to accurately determine the flow rateof the cement flow. In turn, the signals can indicate a measurement ofimpedance, or change in impedance over an interval, or the rate ofchange of impedance of the temperature coefficient material to determinethe viscosity of the cement within the cement flow proximate to the PTCRmaterial or at the flow outlet.

In another aspect of the invention, the method of bone cement injectioncan include modulating the rate of cement flow in response todetermining a selected parameter of the cement flow such as flow rate.The method of bone cement injection can further include applying andmodulating a thermal energy application from an emitter in the injectorbody to the cement flow. The method of bone cement injection can furtherinclude modulating the application of energy in response to signals thatrelate to a selected parameter such as flow rate of the cement flow.

Of particular interest, another method of bone cement injection caninclude (a) providing a bone cement injector body 120 carrying a PTCR(positive temperature coefficient of resistance) material in a flowchannel therein, (b) applying a selected level of energy to a cementflow through the PTCR material, and (c) utilizing an algorithm thatprocesses impedance values of the PTCR material to determine the cementflow rate. The method of bone cement injection further includesmodulating a cement injection parameter in response to the processedimpedance values.

Of particular interest, another method of bone cement injection caninclude (a) providing a bone cement injector body 120 carrying a PTCRmaterial or other thermal energy emitter in a flow channel therein, (b)causing a selected cement flow rate and a selected level of energydelivery to the cement flow through the emitter, and (c) modulating theselected flow rate and/or energy delivery to maintain a substantiallyconstant impedance value of the emitter material over a cement injectioninterval. The selected cement injection interval can be at least 1minute, at least 5 minutes, at least 10 minutes and at least 15 minutes.In another aspect of the invention, the method modulates the selectedflow rate and/or energy delivery to maintain a substantially constantviscosity of bone cement injected from the injector 120 over a cementinjection interval. The system and energy source 140 is configured forapplying energy of at least 0.01 Watt, 0.05 Watt, 0.10 Watt, 0.50 Wattand at least 1.0 Watt. However, the system and energy source 140 can inone embodiment apply more than 1.0 Watt. In another aspect, the energysource 140 and controller 145 can accelerate the polymerization rate ofthe bone cement 150 to a selected (e.g., predetermined) endpoint in lessthan 1 second, 5 seconds, 10 seconds, 20 seconds, 30 seconds, 45seconds, 60 seconds and 2 minutes.

In another embodiment of the invention, the accelerated polymerizationcement 150′ of FIGS. 12A-12D can be further “pre-treated” by the body200 or prior to introduction into the cement-carrying structure 105′ toprovide a cement 150 in the form of an emulsion. By the term emulsion,it is meant that a cement 150 such as PMMA is mixed with anotherbiocompatible fluid that is not well absorbed in the cement 150 such assaline solution. In one embodiment, it has been found that a uniformPMMA-saline emulsion can be created by mechanical activation of thejust-mixed PMMA components together with a saline solution. Such anemulsion can be created by stirring the components with a paddle at arelatively high speed, e.g., a small paddle at at least 100 rpm, 500rpm, 1000 rpm, 5000 rpm, and 10,000 rpm. It has been found that thefinal modulus of such a cured polymer emulsion may be useful forsupporting a vertebra 172 as the modulus is somewhat less that aconventional non-emulsion PMMA.

Another method of bone cement injection can utilize an apparatus asdescribe above and comprises (a) providing a bone cement injector body120 with a flow channel 112 extending therethrough from a proximalhandle end 116 though a medial portion to a distal end portion having aflow outlet, (b) causing cement flow through the flow channel, and (c)warming the cement flow with an energy emitter 144 in a proximal end ormedial portion thereof to initiate or accelerate polymerization of thecement 150 of the cement flow to a selected (e.g. predetermined) level.The method includes providing a flow rate of the cement flow that rangesfrom 0.1 cc/minute to 20 cc/minute, from 0.2 cc/minute to 10 cc/minute,and from 0.5 cc/minute to 5 cc/minute.

Of particular interest, the above-described method of bone cementinjection can allow a predetermined cement flow rate to provide aselected interval in which the cement flows is allowed to polymerize inthe flow channel downstream from the energy emitter. This methodincludes providing a selected interval of greater than 1 second, greaterthan 5 seconds, greater than 10 seconds, greater than 20 seconds, andgreater than 60 seconds.

The above-described method utilizes an energy emitter 144 that appliesenergy sufficient to elevate the temperature of the bone cement 150 byat least 1° C., at least 2° C., and at least 5° C. The method of bonecement injection includes utilizing an energy emitter 144 that appliesat least 0.1 Watt of energy to the cement flow, at least 0.5 Watt ofenergy to the cement flow, and at least 1.0 Watt of energy to the cementflow. The method includes the flow rate of the cement flow beingadjusted in intervals by controller 145, or being continuously adjustedby a controller 145.

The above description of certain embodiments of the invention isintended to be illustrative and not exhaustive. Particularcharacteristics, features, dimensions and the like that are presented independent claims can be combined and fall within the scope of theinvention. The invention also encompasses embodiments as if dependentclaims were alternatively written in a multiple dependent claim formatwith reference to other independent claims. Specific characteristics andfeatures of the invention and its method are described in relation tosome figures and not in others, and this is for convenience only. Whilethe principles of the invention have been made clear in the exemplarydescriptions and combinations, it will be obvious to those skilled inthe art that modifications may be utilized in the practice of theinvention, and otherwise, which are particularly adapted to specificenvironments and operative requirements without departing from theprinciples of the invention. The appended claims are intended to coverand embrace any and all such modifications, with the limits only of thetrue purview, spirit and scope of the invention.

Of course, the foregoing description is that of certain features,aspects and advantages of certain embodiments of the present invention,to which various changes and modifications can be made without departingfrom the spirit and scope of the present invention. Moreover, the bonetreatment systems and methods need not feature all of the objects,advantages, features and aspects discussed above. Thus, for example,those skilled in the art will recognize that the invention can beembodied or carried out in a manner that achieves or optimizes oneadvantage or a group of advantages as taught herein without necessarilyachieving other objects or advantages as may be taught or suggestedherein. In addition, while a number of variations of the invention havebeen shown and described in detail, other modifications and methods ofuse, which are within the scope of this invention, will be readilyapparent to those of skill in the art based upon this disclosure. It iscontemplated that various combinations or subcombinations of thesespecific features and aspects of embodiments may be made and still fallwithin the scope of the invention. Accordingly, it should be understoodthat various features and aspects of the disclosed embodiments can becombined with or substituted for one another in order to form varyingmodes of the discussed bone treatment systems and methods.

What is claimed is:
 1. A system for treating a vertebra, comprising: atleast one elongated cement-carrying structure having an interior spacefor receiving a bone fill material; an energy source operativelycoupleable to an energy emitter configured to apply energy to thecement-carrying structure while the cement-carrying structure is outsideof a patient's body, the energy emitter configured to apply thermalenergy to the bone fill material to selectively accelerate apolymerization rate of the bone fill material; and an elongatedinjector, at least a portion of which is insertable into a vertebralbody, the elongated injector comprising a passageway sized to removablyreceive at least a portion of the elongated cement-carrying structure soas to allow delivery of the bone fill material with said acceleratedpolymerization rate through the injector into the vertebral body,wherein the energy emitter is separate from the cement-carryingstructure and the elongated injector, wherein the energy source iscoupleable to a housing, the housing comprising the energy emitter andconfigured for releasably and mainly receiving the at least onecement-carrying structure in an elongated passage thereof.
 2. The systemof claim 1, wherein the energy source is coupleable to a controller. 3.The system of claim 2, further comprising a cooling system operativelycoupled to a housing, wherein the controller is configured to controlthe cooling system to selectively retard the polymerization of the bonefill material.
 4. The system of claim 2, further comprising a dataacquisition system coupleable to the controller, wherein the dataacquisition system is configured to communicate with the controller andprovide a signal of at least one polymerization parameter of the bonefill material.
 5. The system of claim 1, further comprising a pressuremechanism operatively coupleable to the elongated cement-carryingstructure for moving the bone fill material through the cement-carryingstructure and injector into the vertebral body.
 6. The system of claim1, wherein the energy source comprises a resistive heat source.
 7. Thesystem of claim 1, wherein the energy source comprises a positivetemperature coefficient of resistance (PTCR) constant temperature heatsource.
 8. The system of claim 1, wherein the selectively acceleratedpolymerization rate increases the viscosity of the bone fill material.9. A system for treating bone comprising: an elongated injector, atleast a portion of which insertable into a bone; at least one elongatedcement-carrying structure configured to contain a volume of a mixed bonefill material, the cement carrying structure releasably coupleable tothe injector; and at least one housing member comprising an energyemitter and sized to removably and mainly receive the at least onecement-carrying structure in an elongated passage thereof, the energyemitter configured to apply thermal energy to the bone fill materialoutside of a patient's body when the cement-carrying structure iscoupled to the housing and prior to coupling of the cement-carryingstructure to the elongated injector to thereby selectively acceleratepolymerization of the mixed bone fill material, wherein the housingmember is separate from the elongated injector.
 10. The system of claim9, wherein ihe at least one cement-carrying structure comprises aplurality of cement-carrying structures and wherein the at least onehousing member comprises a plurality of housing members corresponding tothe plurality of cement-carrying structures.
 11. The system of claim 10,wherein the energy source is coupleable to a controller, wherein thecontroller is configured to controlt he energy emitter to accelerate therate of polymerization of the mixed bone fill material.
 12. The systemof claim 11, further comprising a cooling system coupled to thehousing,t he controller connected to the cooling system and configuredto control the operation of the cooling system to retard thepolymerization of bone fill material.
 13. The system of claim 11,further comprising a data acquisitions ystem coupleable to thecontroller, whereint he data acquisition system is configured tocommunicate with the controller and provide a signal of at least onepolymerization parameter of the bone fill material.
 14. The system ofclaim 9, wherein the energy emitter is coupleable to an energy source.15. The system of claim 9, wherein the energy emitter comprises aresistive heat source.
 16. The system of claim 9, wherein the energyemitter comprises a positive temperature coefficient of resistance(PTCR) constant temperature heat source.
 17. The system of claim 9,wherein the selectively accelerated polymerization increases theviscosity of the mixed bone fill material.